Originally Posted by F4E Mx

Could it have been something as simple as the aircraft flying into a massive downdraft/wind shear with the autopilot engaged with an altitude select function still engaged as well? The autopilot's reaction was at odds with what normally have been done manually, namely level the nose and apply a lot of power to arrest the descent. The airplane basically stalled, they punched off the autopilot and added max power but it was too late.